ppc/xive: Rework setup of XiveSource::esb_mmio

Depending on whether XIVE is emultated or backed with a KVM XIVE device,
the ESB MMIOs of a XIVE source point to an I/O memory region or a mapped
memory region.

This is currently handled by checking kvm_irqchip_in_kernel() returns
false in xive_source_realize(). This is a bit awkward as we usually
need to do extra things when we're using the in-kernel backend, not
less. But most important, we can do better: turn the existing "xive.esb"
memory region into a plain container, introduce an "xive.esb-emulated"
I/O subregion and rename the existing "xive.esb" subregion in the KVM
code to "xive.esb-kvm". Since "xive.esb-kvm" is added with overlap
and a higher priority, it prevails over "xive.esb-emulated" (ie.
a guest using KVM XIVE will interact with "xive.esb-kvm" instead of
the default "xive.esb-emulated" region.

While here, consolidate the computation of the MMIO region size in
a common helper.

Suggested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159679992680.876294.7520540158586170894.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index 705cf48176..82a61eaca7 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -191,6 +191,7 @@ typedef struct XiveSource {
     uint64_t        esb_flags;
     uint32_t        esb_shift;
     MemoryRegion    esb_mmio;
+    MemoryRegion    esb_mmio_emulated;
 
     /* KVM support */
     void            *esb_mmap;
@@ -215,6 +216,11 @@ static inline bool xive_source_esb_has_2page(XiveSource *xsrc)
         xsrc->esb_shift == XIVE_ESB_4K_2PAGE;
 }
 
+static inline size_t xive_source_esb_len(XiveSource *xsrc)
+{
+    return (1ull << xsrc->esb_shift) * xsrc->nr_irqs;
+}
+
 /* The trigger page is always the first/even page */
 static inline hwaddr xive_source_esb_page(XiveSource *xsrc, uint32_t srcno)
 {